I am no expert on the topic but I strongly feel you would be hard pressed to find a better documentary series on the Vietnam war than Vietnam: The Ten Thousand Day War. Originally produced for and aired on the CBC in 1981, this 26 part series was written by Associated Press journalist Peter Arnett who spent 13 years covering Vietnam. Producer Michael Maclear was the first to have access to footage from Vietnamese forces. All of the episodes informative and sound balanced to this viewer. This documentary's only weak point is some clips are used five or six times over the series otherwise it is worth every penny. Available at Amazon U.S.
Vietnam The Ten Thousand Days War opens with the beginnings of U.S. Involvement in Vietnam after the country was separated in two. The second episode goes back to French involvement in what was one of its Asian colonies. Other half-hour episodes cover Diem Bien Phu where the French lost (DVD 1), the Tet offensive (DVD 3), Westmoreland's role in the Vietnam war (DVD 2), and the prisoners taken bu the North (DVD 4) to name but a few.
All the episodes are interesting but a couple are more so only because they tell an aspect of the story few are that familiar with. One of these is The Trail (DVD 2) on how the North Vietnamese built the Ho Chi Minh trail and kept it open throughout the war. Anyone looking at the determination of every man, woman, and child working on the trail can see why the North Vietnamese forces won in the end.
Another, though too short for my taste, is Vietnam Recalled (DVD 4) where soldiers from a slamm town in Kentucky recall their experiences as well as a look at what Vietnam had become by 1980.
This 4 DVD documentary set features a who's who of the people involved in the conflict. This includes major figures from North and South Vietnam as well as Americans such as soldier and author Tim O'Brien (Going After Cacciato and The Things They Carried), marine Jack McCloskey, General William Westmoreland, CIA director William Colby, and Kennedy advisor Henry Cabot Lodge to name but a few.
Other VSC titles we liked:
The WHA Chronicles, a documentary about the WHA with complete game footage.
The Roller Derby Chronicles 3 DVD set